Process of grooving laminated glass



July 17, 1934. E. H. HAUX 1,966,817

PROCESS OF GROOVING LAMINATED GLASS Filed April 8, 1933 INVENTOR UNITED STATES PATENT OFFICE PROCESS OF GROOVING LAIVHNATED GLASS Elmer H. Haux, Tarentum, Pa., assignor to Duplate Corporation, a corporation of Delaware Application April 8, 1933, Serial No. 665,120

Claims. (Cl. 204-1) The invention relates to a process of grooving Referring to the drawing, 1 is a steel tank conlaminated glass which ordinarily consists of two taining sulphuric acid of about 98 per cent consheets of glass secured to the opposite faces of a centration; 2 is a rack, preferably of chrome sheet of reinforcing material, such as cellulose nickel steel for supporting the plates 3; 4 is a 5 plastic, the materials most commonly used being chain or cable for raising and lowering the rack 60 cellulose nitrate and cellulose acetate. In order by means of a suitable hoist (not shown); 4a is to protect this reinforcing interlayer, it is the a wood or composition block interposed in the practice to remove it from the edge of the plate to chain for the purpose of insulation; 5 is a motor a distance of about inch, and seal the resultant whose shaft 6 is provided with blades 7 for agitatgroove with a water-proof protective compound. ing the bath; 8 is a steam coil for heating the 65 Concentrated sulphuric acid has been found to be bath; 9 is a thermo couple for temperature detersatisfactory for grooving out the interlayer. mination; and 10 and 11 are terminals from 2. However, since the reaction is primarily one of source of direct current supply. dehydration, a deposit of insoluble carbon is The plates 3 t be v d. a Consisting of 1 formed, and attaches itself to the periphery of w heets of lass c mented to the opp sides 70 the plate. This retards to some extent the uni- Of a Sheet of organic reinforcing material are form action of the acid. The object of the present Stacked in t a as shown, with Sheets 12 f invention is the provision of an improvement g t a Steel sp s d between the P whereby the carbon is removed, and faster and The h i pr f r ly maintain d at a t mp r more uniform grooving is r d, ture of about 200 degrees F., and during the oper- 75 Briefly stated, the de ir d 1t i aeeomation, the liquid of the bath is vigorously agitated plished by supporting the laminated plates to be circulated y a s f th ades 7 0f the grooved in a metal rack in the acid bath, and tatihg device The ta k iS ad the negative passing a current of electricity through the bath D of the u t y C nn t n w t t negative with the rack connected to the positive terminal rm 11, nd the rack the p sitiv r y so of the source of current. The formation of the Connection W the p s terminal The carbon deposit, heretofore referred to, on the Current q d s. depending on the Size 0f periphery of the plate, causes this portion of the the tank and the character of the interlayer to be glass to become an electrical conductor, and since grooved With a tank nc es y 98 inches the plate is carried by the metal rack, the entire having a d p of 66 i s. g d results are 85 periphery of the plate becomes a part of the posi-- cured with 4 amperes of current and a voltage of tive pole of the circuit. The passage of the curthe grooving accomplished being Substantially rent through the bath decomposes some of the more rapid n nif m h n is the case where water, liberating oxygen at the positive pole, the grooving is accomplished under similar conwhich oxygen unites with the carbon forming ditions without the use of the electrical current. 90

CO2. This gas escapes from the bath, thus leav- In grooving plates which have a r inforcin intering the plate free from carbon, layer of cellulose acetate, the bath will in time Since the carbon is gotten rid of as it is formed, become contaminated with acetic acid, but this faster and more uniform grooving results. A fury be removed y Periodically boiling OIT when ther advantage lies in the fact that the sulphuric it becomes j t o able- 9 acid concentration in the bath will always re- The use of the electric current is also of advanmain constant. The action of the acid on the tage in grooving with corrosive liquids other than cellulose plastic is a dehydrating one, and the sulphuric acid, such as mixed acid (nitric acid water thus liberated in part, at least, furnishes plus su p u a d), f rmic a id. nitric acid and the oxygen necessary for regeneratingv the acid the like, the groov g in all cases being ac e d Any additional water required for this purpose by passing t c cu through the bath with is supplied by absorption from the atmosphere, the pla to be grooved a p the p i v elecor by deliberate addition. One form of apparatus trode. With the use of acid other than the sulwhich may be used in practicing the invention is phur or mix d acids. the reaction s app ntly 50 shown in the accompanying drawing, wherein: one of concentration and solution rather than of Figure l is a vertical section through the comdehydration and oxidation. plete apparatus. And Fig. 2 is a perspective view What I claim is: on an enlarged scale of the rack employed with 1. A process of accelerating the grooving of a. the laminated plates to be grooved support-ed plate of composite glass made up of a sheet of 55 therein. reinforcing material lying between a pair of glass sheets, and immersed in a bath of corrosive liquid of sufiicient concentration to decompose the reinforcing material, which consists in passing a current of electricity through the bath.

2. A process of accelerating the grooving of a plate of composite glass made up of a sheet of reinforcing material lying between a pair of glass sheets, and immersed in a bath of corrosive liquid of suflicient concentration to decompose the reinforcing material, which consists in passing a current of electricity through the bath, with the composite plate as a part of the positive electrode of the cell.

3. A process of accelerating the grooving of a plate of composite glass made up of a sheet of organic reinforcing material lying between a pair of glass sheets and immersed in a concentrated acid bath, which consists in passing a current of electricity through the bath with the composite plate as a part of the positive electrode of the cell.

4. A process of accelerating the grooving of a plate of composite glass made up of a sheet of organic reinforcing material lying between a pair of glass sheets and immersed in a bath of concentrated sulphuric acid, which consists in pass-- ing a current of electricity through the bath with the composite plate as a part of the positive electrode of the cell.

5. A process of accelerating the grooving of a plate of composite glass made up of a sheet of cellulose plastic reinforcing material lying between apair of glass sheets and immersed in an acid bath, which consists in passing a current of electricity through the bath with the composite plate as a part of the positive electrode of the cell. 

